This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We are studying the consequences of chronic pain on astrocytes in the spinal cord. In order to complement electrophysiological measurements being made on spinal astrocytes, we would like to examine changes in the morphology of astrocytes at the light and electron microscopic levels. We would like to approach this with a combination of fluorescent dye cell fills, photoconversion, and electron tomography.